Triazine-containing carbazole compound and application thereof

Abstract

The invention provides a triazine-containing carbazole compound and application thereof, the triazine-containing carbazole compound has a structure as shown in a formula I. The triazine-containing carbazole compound obtained by designing the structure of the triazine-containing carbazole compound has good luminescence performance, can be used for preparing organic electroluminescent devices, and can be used for preparing organic electroluminescent devices. Particularly, as a green light main body material in the organic electroluminescent device, the compound can effectively reduce the driving voltage of the organic electroluminescent device and improve the current efficiency of the organic electroluminescent device.

Description

Technical Field

[0001] The invention belongs to the technical field of organic photoelectric technology, and specifically relates to a triazine-containing carbazole compound and application thereof. Background Art

[0002] Organic light emitting diodes (OLED) device technology can be used to manufacture new display products as well as new lighting products. It is expected to replace existing liquid crystal displays and fluorescent lighting, and has a broad application prospect.

[0003] Organic Light Emitting Diode (OLED) is abbreviated as OLED display. It has the characteristics of self-luminescence. It is composed of a very thin organic material coating and a glass substrate to form a "sandwich" structure. The entire structural layer includes a hole transport layer (HTL), a light-emitting layer (EL) and an electron transport layer (ETL). When an appropriate voltage is applied to it, these organic light-emitting materials will emit a specific light. Due to the self-luminous characteristics of OLED, it does not require a backlight source, has low voltage requirements and saves electricity. In addition, OLED has the characteristics of stable performance and excellent color display, and has broad application prospects in the fields of display and lighting.

[0004] At present, although the application scope of OLED is constantly expanding and the products of OLED display technology have been gradually industrialized, there are still shortcomings. The research and development of luminescent materials is a popular direction to solve the problem. For the field of OLED technology, it is particularly important to develop a high-performance OLED luminescent material. Through material innovation, the driving voltage of the device can be optimized, the luminous efficiency and display effect of OLED devices can be improved, and the service life of OLED devices can be extended. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention aims to provide a triazine-containing carbazole compound and its application. The present invention is designed through the structure of the triazine-containing carbazole compound, and the obtained triazine-containing carbazole compound has excellent performance and is suitable for use as a green light host material in an organic electroluminescent device.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] In one aspect, the present invention provides a triazine-containing carbazole compound, wherein the triazine-containing carbazole compound has a structure as shown in the following formula I:

[0008]

[0009] Wherein, R1 and R2 are each independently selected from C6 to C40 aryl groups;

[0010] R3 and R4 are each independently selected from C6 to C 40 Aryl or C3~C 30 heteroaryl;

[0011] The hydrogen atoms in the compound of formula I may be independently substituted by at least one of a deuterium atom, F, CN, a C1-C10 alkyl group or a C6-C20 aryl group.

[0012] Preferably, the C6-C40 aryl group is selected from any one of phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthryl, dibenzofluorenyl, pyrenyl, perylenyl or triphenylene.

[0013] Preferably, the heteroatom in the C3-C30 heteroaryl group is an oxygen or sulfur atom;

[0014] Preferably, the C3-C30 heteroaryl group is selected from any one of benzofuran, benzothiophene, dibenzofuran or dibenzothiophene.

[0015] Preferably, the hydrogen atoms in the compound of formula I can be independently substituted by at least one of -D, F, CN, methyl, ethyl, propyl, butyl or phenyl.

[0016] Preferably, the compound includes any one of the following compounds:

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027] Preferably, the triazine-containing carbazole compound is selected from any one of compounds 1-20:

[0028]

[0029] The present invention lists some specific structural forms of the triazine-containing carbazole compounds, but the triazine-containing carbazole compounds of the present invention are not limited to these listed chemical structures, and all structures based on the structure shown in Formula I and in which R1, R2, R3, and R4 meet the above-mentioned limiting conditions should be included.

[0030] In a second aspect, the present invention provides an organic electroluminescent device, wherein the organic electroluminescent device comprises the triazine-containing carbazole compound as described in the first aspect.

[0031] Preferably, the organic electroluminescent device comprises a first electrode, a second electrode and an organic layer disposed between the first electrode and the second electrode; the material of the organic layer comprises the triazine-containing carbazole compound as described in the first aspect.

[0032] Preferably, the organic layer comprises a light-emitting layer; the material of the light-emitting layer comprises the triazine-containing carbazole compound as described in the first aspect.

[0033] In a third aspect, the present invention provides a display device, comprising the organic electroluminescent device as described in the second aspect.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The present invention designs the structure of a triazine-containing carbazole compound to obtain a triazine-containing carbazole compound with good luminescence performance, which can be used to prepare an organic electroluminescent device, especially as a green light host material in an organic electroluminescent device, and can effectively reduce the driving voltage of the organic electroluminescent device and improve the current efficiency of the organic electroluminescent device. DETAILED DESCRIPTION

[0036] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0037] Synthesis Example 1

[0038] This embodiment provides a method for synthesizing compound 1, as described below:

[0039]

[0040] Synthesis of Intermediate I

[0041] 0.1 mol of 8-bromo-5-phenyl-11H-benzo[a]carbazole, 0.11 mol of (4,6-diphenyl-1,3,5-triazine-2-yl)boric acid, 0.15 mol of potassium carbonate, 0.003 mol of tetrakis(triphenylphosphine)palladium, 300 mL of toluene, 100 ml of ethanol, and 100 ml of water were added to a reaction flask, heated to reflux under nitrogen protection, and reacted for 5 hours. After the reaction was completed, the reaction solution was naturally cooled to room temperature, separated, the aqueous phase was extracted with 200 mL of toluene, the organic phases were combined, anhydrous magnesium sulfate was added for drying, anhydrous magnesium sulfate was removed by filtration, the filtrate was passed through a silica gel column to remove the catalyst, and the column liquid was concentrated and recrystallized with ethanol and toluene to obtain intermediate I.

[0042] The mass spectrum data of intermediate I was tested, and the mass spectrum m / z was measured to be 524.20.

[0043] Synthesis of compound 1

[0044] 0.1 mol of intermediate I, 0.11 mol of iodobenzene, 0.003 mol of tris(dibenzylideneacetone)dipalladium, 0.006 mol of (2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl), 0.12 mol of sodium tert-butoxide and 300 ml of xylene were added to a reaction bottle. Under nitrogen protection, the temperature was raised to reflux for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, 500 ml of n-heptane and 200 ml of distilled water were added, stirred for 30 minutes, filtered, 200 ml of distilled water was added to the filter cake and stirred for 30 minutes, filtered, 200 ml of ethanol was added to the filter cake and stirred for 30 minutes, filtered, and the filter cake was vacuum dried to obtain compound 1.

[0045] The mass spectrum data of compound 1 was tested, and the mass spectrum m / z was measured to be 600.23.

[0046] Synthesis Example 2

[0047] This embodiment provides a method for synthesizing compound 2, as described below:

[0048]

[0049] Synthesis of Intermediate II

[0050] The specific preparation method of intermediate II refers to the preparation method of intermediate I in Synthesis Example 1, and the only difference from the preparation method of intermediate I is that the intermediate 8-bromo-5-phenyl-11H-benzo[a]carbazole is replaced by 8-bromo-5-chloro-11H-benzo[a]carbazole to obtain intermediate II.

[0051] The mass spectrum data of intermediate II was tested, and the mass spectrum m / z was measured to be 482.13.

[0052] Synthesis of Intermediate III

[0053] Dissolve 0.1 mol of intermediate II, 0.11 mol of 2-naphthaleneboronic acid, 0.003 mol of Pd(PPh3)4 and 0.15 mol of potassium carbonate in 500 mL of THF and 250 mL of distilled water, and heat to reflux for 6 hours under nitrogen protection. After the reaction is completed, filter, add the filter cake to 400 mL of toluene, heat to dissolve, and pass through a silica gel column. Concentrate the column liquid to 100 mL, add 400 mL of ethanol, stir at room temperature for 1 hour, filter, and vacuum dry the filter cake to obtain intermediate III.

[0054] The mass spectrum data of intermediate III was tested, and the mass spectrum m / z was measured to be 574.22.

[0055] Synthesis of compound 2

[0056] The specific preparation method of compound 2 refers to the preparation method of compound 1 in Synthesis Example 1, and the only difference from the preparation method of compound 1 is that intermediate I is replaced by intermediate III to obtain compound 2.

[0057] The mass spectrum data of compound 2 was tested and the mass spectrum m / z was measured to be 650.25.

[0058] Synthesis Example 3

[0059] This embodiment provides a method for synthesizing compound 3, as described below:

[0060]

[0061] Synthesis of Intermediate IV

[0062] The specific preparation method of intermediate IV refers to the preparation method of intermediate III in Synthesis Example 2, and the only difference from the preparation method of intermediate III is that 2-naphthaleneboric acid is replaced by dibenzo[b,d]furan-4-ylboric acid to obtain intermediate IV.

[0063] The mass spectrum data of intermediate IV was tested, and the mass spectrum m / z was measured to be 614.21.

[0064] Synthesis of compound 3

[0065] The specific preparation method of compound 3 refers to the preparation method of compound 1 in Synthesis Example 1, and the only difference from the preparation method of compound 1 is that intermediate I is replaced by intermediate IV, and iodobenzene is replaced by 1-bromonaphthalene to obtain compound 3.

[0066] The mass spectrum data of compound 4 was tested and the mass spectrum m / z was measured to be 740.26.

[0067] Synthesis Example 4

[0068] This embodiment provides a method for synthesizing compound 4, as described below:

[0069]

[0070] Synthesis of Intermediate V

[0071] The specific preparation method of intermediate V refers to the preparation method of intermediate II in Synthesis Example 2, and the only difference from the preparation method of intermediate II is that (4,6-diphenyl-1,3,5-triazine-2-yl)boric acid is replaced by (4-(naphthalen-2-yl)-6-phenyl-1,3,5-triazine-2-yl)boric acid to obtain intermediate V.

[0072] The mass spectrum data of intermediate V was tested, and the mass spectrum m / z was measured to be 532.15.

[0073] Synthesis of Intermediate VI

[0074] The specific preparation method of intermediate VI refers to the preparation method of intermediate III in Synthesis Example 2, and the only difference from the preparation method of intermediate III is that 2-naphthaleneboric acid is replaced by dibenzothiophene-3-ylboric acid, and intermediate II is replaced by intermediate V to obtain intermediate VI.

[0075] The mass spectrum data of intermediate VI was tested and the mass spectrum m / z was measured to be 680.20.

[0076] Synthesis of compound 4

[0077] The specific preparation method of compound 4 refers to the preparation method of compound 2 in Synthesis Example 2, and the only difference from the preparation method of compound 2 is that intermediate I is replaced by intermediate VI, and iodobenzene is replaced by 2-bromonaphthalene to obtain compound 4.

[0078] The mass spectrum data of compound 4 was tested and the mass spectrum m / z was measured to be 806.25.

[0079] As shown in Table 1, the preparation raw materials and mass spectrometry detection data of Compound 5-Compound 10 are shown in Table 1.

[0080] Table 1

[0081]

[0082]

[0083] Other compounds whose specific synthesis steps are not listed can be prepared by common knowledge in the art in combination with the above embodiments.

[0084] The specific structures of the compounds used in the following device examples and device comparative examples are shown below:

[0085]

[0086] Device Application Example 1

[0087] Application example 1 of the device provides an organic electroluminescent device, and the compound provided by the present invention is selected as the green light main material in the organic electroluminescent device.

[0088] The structure of the organic electroluminescent device is: ITO / NPB (20nm) / green light host material (35nm): Ir(ppy)3[10%] / TPBI (10nm) / Alq3 (15nm) / LiF (0.5nm) / Al (150nm). "Ir(ppy)3[10%]" refers to the doping ratio of the green light dye, that is, the volume ratio of the green light host material to Ir(ppy)3 is 90:10.

[0089] The organic electroluminescent device preparation process is as follows:

[0090] (1) a glass plate coated with an ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment until the water was completely removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam;

[0091] (2) Place the glass substrate with the anode in a vacuum chamber and evacuate the chamber to a vacuum of 1×10 -5 ~9×10 -4 Pa, vacuum evaporating a hole transport layer NPB on the above anode layer film, the evaporation rate is 0.1nm / s, and the evaporation film thickness is 20nm;

[0092] (3) vacuum evaporating a green light host material and a dye Ir(ppy)3 on the hole transport layer as the light-emitting layer of the organic electroluminescent device, with an evaporation rate of 0.1 nm / s and a total evaporation film thickness of 35 nm;

[0093] (4) vacuum evaporating the electron transport layer TPBI and Alq3 on the light-emitting layer in sequence, with the evaporation rate of each being 0.1 nm / s and the evaporation film thickness being 10 nm and 15 nm respectively;

[0094] (5) 0.5 nm of LiF and 150 nm of Al were vacuum-deposited on the electron transport layer as the electron injection layer and cathode.

[0095] Device Examples 2-10

[0096] Device Examples 2-10 respectively provide an organic electroluminescent device, which differs from Device Example 1 only in that the green light host material is different (see Table 2 below for details), and other conditions are the same as those of Device Example 1.

[0097] Device Comparison Examples 1-3

[0098] Device Comparative Examples 1-3 respectively provide an organic electroluminescent device, which differs from Device Example 1 only in that the green light host material is different (see Table 2 below for details), and other conditions are the same as those of Device Example 1.

[0099] Performance Test:

[0100] The brightness, driving voltage, current efficiency and life test LT90 of the organic electroluminescent device provided above are tested, wherein the life test LT90 refers to the current density at room temperature (25-27°C) at the initial brightness (1000 cd / m 2 ), the time required for the brightness to decrease to 90% of the initial brightness. In the following table, the driving voltage, current efficiency, and LT90 life are all relative values ​​(based on the test data of device comparative example 1). The test results are detailed in Table 2 below.

[0101] Table 2

[0102]

[0103] It can be seen from the content of Table 2 that the present invention obtains triazine-containing carbazole compounds through molecular design. The triazine-containing carbazole compounds provided by the present invention can be used as green light host materials of OLED light-emitting devices, so that the OLED light-emitting devices have lower driving voltage, higher current efficiency and longer life.

[0104] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the triazine-containing carbazole compounds and their applications, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A triazine-containing carbazole compound, characterized in that: The triazine-containing carbazole compound has a structure shown in the following formula I: Wherein, R1 and R2 are each independently selected from C6 to C40 aryl groups; R3, R4 are selected from C6~C 40 Aryl or C3~C 30 heteroaryl; The hydrogen atoms in the compound of formula I may be independently substituted by at least one of a deuterium atom, F, CN, a C1-C10 alkyl group or a C6-C20 aryl group.

2. The triazine-containing carbazole compound according to claim 1, characterized in that: The C6-C40 aryl group is selected from any one of phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthryl, dibenzofluorenyl, pyrenyl, perylenyl or triphenylene.

3. The triazine-containing carbazole compound according to claim 1 or 2, characterized in that: The heteroatom in the C3-C30 heteroaryl group is an oxygen or sulfur atom; Preferably, the C3-C30 heteroaryl group is selected from any one of benzofuran, benzothiophene, dibenzofuran or dibenzothiophene.

4. The triazine-containing carbazole compound according to any one of claims 1 to 3, characterized in that: The hydrogen atoms in the compound of formula I may be independently substituted by at least one of -D, F, CN, methyl, ethyl, propyl, butyl or phenyl.

5. The triazine-containing carbazole compound according to any one of claims 1 to 4, characterized in that: The compound includes any one of the following compounds:

6. The triazine-containing carbazole compound according to any one of claims 1 to 5, characterized in that: The triazine-containing carbazole compound is selected from any one of compounds 1-20:

7. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises the triazine-containing carbazole compound according to any one of claims 1 to 6.

8. The organic electroluminescent device according to claim 7, characterized in that: The organic electroluminescent device comprises a first electrode, a second electrode and an organic layer disposed between the first electrode and the second electrode; the material of the organic layer comprises the triazine-containing carbazole compound as claimed in any one of claims 1 to 6.

9. The organic electroluminescent device according to claim 7 or 8, characterized in that: The organic layer includes a light-emitting layer; the material of the light-emitting layer includes the triazine-containing carbazole compound as claimed in any one of claims 1 to 6.

10. A display device, characterized in that: The display device comprises the organic electroluminescent device according to any one of claims 7 to 9.

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